1. Field of the Invention
The present invention relates to a new magnetic recording medium having magnetic tracks arranged substantially concentrically for writing and reading magnetic information, and discrete portions for magnetically separating the magnetic tracks located adjacent to each other in a radial direction, to thereby record magnetization information in a width direction of each magnetic track, and further relates to a new magnetic recording and reproducing system employing such a magnetic recording medium.
2. Description of the Related Art
For the purpose of reducing influence between the adjacent magnetic tracks to thereby realize a high track density, there have been proposed so-called discrete track mediums that are provided with magnetically separating layers (discrete portions) at gap portions between the adjacent magnetic tracks. Presently, the proposed discrete track mediums are roughly classified into two types depending on a direction of recorded magnetization information, i.e. the discrete track medium of the in-plane longitudinal recording type where the magnetization information is recorded in an in-plane longitudinal direction along a circumferential direction of the medium, and the discrete track medium of the perpendicular recording type where the magnetization information is recorded in a thickness direction of a recording layer.
In case of the discrete track medium of the in-plane longitudinal recording type, following improvement in linear recording density, it is necessary to enhance a coercivity (HC) of the medium for preventing demagnetization caused by a demagnetization field, and there arises a tendency that recording by a magnetic head becomes difficult in the medium having a high coercivity.
On the other hand, in case of the discrete track medium of the perpendicular recording type, it is necessary to achieve a sharp recording magnetic field for realizing a high recording density. For this purpose, it is necessary to provide a thick high magnetic permeability layer under the medium recording layer, and therefore, there arise problems of increase in manufacturing cost of the medium and occurrence of noise due to movement of magnetic domain walls in the thick high magnetic permeability layer.
As one means for solving such problems, a method of recording (in-plane width direction recording or transverse magnetic recording) in a width direction of each magnetic track can be considered as one interesting technique.
However, with respect to such a recording technique in the magnetic track width direction, realization of recording and reproduction is practically quite difficult, and therefore, there have been no specific proposals about structures of a recording medium and a recording and reproducing system.
The present invention has been made under these circumstances, and has an object to provide a new magnetic recording medium that enables realization of the recording and reproduction in the magnetic track width direction, and further provide a new recording and reproducing system.
Owing to such a new magnetic recording medium and such a new recording and reproducing system, there are achieved various merits derived from the recording and reproduction in the magnetic track width direction, such as (1) while being of the in-plane recording type, the medium causes no self-demagnetization even in high linear recording density, and therefore, it is not necessary to greatly enhance a coercivity of the medium, so that designing of a recording head is facilitated, (2) there are no demagnetization fields between recording bits, and therefore, a thickness of a magnetic layer of the medium can be increased as compared with the conventional longitudinal direction recording, so that it is possible to improve a problem of loss of magnetization information caused by thermal fluctuation, (3) a gap length of a magnetic head is about a magnetic track width of the medium, so that designing of the magnetic head is facilitated, and (4) owing to the discrete track structure, higher track densification is made possible.